The present invention relates generally to seats and more particularly to seats for mass transit vehicles such as buses or rapid transit cars.
Conventionally, seats for mass transit vehicles comprise a steel frame on which is mounted a seat cushion and a back cushion. For aesthetic purposes, the exposed portions of the frame, not covered by the seat cushion or back cushion, are covered by an exterior decorative plastic shell at the back and exterior decorative plastic members along the sides.
Certain problems arise in conventional seat constructions utilizing metal seat frames and exterior plastic shells or decorative members. For example, the exterior plastic decorative members and shell are typically assembled to the metal seat frame with metal fasteners. These fasteners can be removed by vandals resulting in the assembly coming apart and rendering the plastic parts readily susceptible to pilferage. In addition, the metal seat frame has a different coefficient of thermal expansion than the plastic of which the exterior decorative members and shell are composed. Accordingly, stresses can develop at the location where the fasteners secure these plastic parts to the metal frame, and this can produce cracks or damage to the exterior plastic parts as the plastic parts and the metal parts undergo different amounts of thermal expansion.